VHS quality will still be VHS quality copied onto a BD. Copy them onto DVDs. You'll get the same quality.

you would be able to fit a lot more on a Bluray then DVD, however, it probably does make more sense financially to just put them on DVDs.

dvd burners are ridiculously cheap now, as are blank dvds. bluray media and recorders are still fairly expensive, so unless there's some dire reason you need it on a bluray sticking to dvd backup might be the more efficient solution.

My name is Patrick Bateman. I'm 27 years old.
I believe in taking care of myself and a balanced
diet and rigorous exercise routine. In the morning,
if my face is a little puffy, I'll put on an ice pack while
doing stomach crunches. I can do a thousand now.